Comparison · Silicate Minerals
Moss Agate vs Staurolite
Moss Agate and Staurolite are easy to confuse because both are silicate minerals. Both sit near Mohs 6.75, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Below is a side-by-side comparison of their properties and the quick tests that separate them.
Key differences between Moss Agate and Staurolite
- Both sit near Mohs 6.75, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
- Streak color differs: Moss Agate leaves a white streak on unglazed porcelain, Staurolite leaves white to grayish.
- Staurolite feels noticeably heavier for its size (specific gravity 3.7 versus 2.62 for Moss Agate).
- They overlap in brown and black, but Moss Agate also comes in clear and green and Staurolite also comes in red.
- Well-formed crystals give it away: Moss Agate is trigonal, Staurolite is monoclinic.
Moss Agate vs Staurolite properties
| Property | Moss Agate | Staurolite |
|---|---|---|
| Type | Silicate Minerals | Silicate Minerals |
| Mohs hardness | 6.75 | 7.25 |
| Luster | vitreous | vitreous |
| Streak | White | White to grayish |
| Transparency | translucent | translucent |
| Specific gravity | 2.62 | 3.7 |
| Crystal system | trigonal | monoclinic |
| Common colors | Colorless, White, Green, Brown, Black | Reddish brown, Brown, Dark brown, Black |
| Rarity | common | uncommon |
| Typical specimen value | $5–$150+ | $5–$300+ |
Which is more valuable?
Staurolite is usually the more valuable of the two: a typical collector specimen runs about $45 against $30 for Moss Agate, and premium Staurolite can reach $300 or more.
About Moss Agate
Moss agate is a translucent chalcedony filled with green, brown, or black mineral inclusions that resemble moss or foliage. Despite the name it contains no organic material, and it is widely cut for jewelry.
About Staurolite
Staurolite is an iron aluminum silicate famous for its cross-shaped twinned crystals. It forms reddish-brown to nearly black prismatic crystals in metamorphic schists and is a classic index mineral of medium-grade metamorphism.
Moss Agate vs Staurolite FAQ
Is Moss Agate the same as Staurolite?
No. Both are silicate minerals, but they are distinct species with different hardness, streak or luster. Both sit near Mohs 6.75, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
How can you tell Moss Agate from Staurolite?
Both sit near Mohs 6.75, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Streak color differs: Moss Agate leaves a white streak on unglazed porcelain, Staurolite leaves white to grayish. Staurolite feels noticeably heavier for its size (specific gravity 3.7 versus 2.62 for Moss Agate).
Which is harder, Moss Agate or Staurolite?
Staurolite is harder: Mohs 7.25 against Mohs 6.75 for Moss Agate.
Which is more valuable, Moss Agate or Staurolite?
Staurolite is usually the more valuable of the two: a typical collector specimen runs about $45 against $30 for Moss Agate, and premium Staurolite can reach $300 or more.
